If the old model for newspapers was one size fits all, just one edition per day, whether for 2,000 or 200,000 readers, the new model is the fully customized newspaper, an edition for every possible need in whatever format the reader may want.

The latest format is, of all things, the PDF. Though they've yet to catch on in the U.S., PDF editions are rolling out in Canada, the UK and elsewhere. The idea was initially developed at the Financial Times of London.

One might think a newspaper in PDF format would have only slight appeal, but publishers see real potential. For one, the PDF is highly portable, fit for printing out on short notice, which makes it ideal for people heading into meetings, for example.

And the printed version, at 8.5 by 11 inches, fits easily into briefcases for reading on the train on the way home or folders for filing. And if a printout is lost, another can be done up quickly.

For publishers, there's no real added cost for PDF editions, in terms of paper and ink and distribution, since it is delivered by email. And it offers yet another means of reaching readers and providing advertisers exposure.

At the Toronto Star, Canada's largest daily, its PDF edition is called Star PM, and at the Ottawa Citizen it goes by the name of RushHour. Subscribers to these PDF editions receive them by email for reading in free Acrobat Readers, either on their computer or portable devices such as a BlackBerry.

Star PM, which was launched on Sept. 5, goes out at 3:30 p.m. Monday through Friday. It's 12 pages. There also a 4:15 edition with business updates.

Ottawa RushHour, launched in November, is a hybrid publication, with a 1 p.m. weekday PDF edition sent by email and a 4 p.m. edition that's handed out by street hawkers in Ottawa's downtown and available in boxes. It runs 12 to 20 pages and some 8,000 copies are distributed.

Advertisers like the print version of RushHour, says Lynne Clark, market development manager of the Ottawa Citizen. "Advertisers have embraced the product because 80 percent of the print product is distributed by hawkers who place it directly into the hands of target readers. The pickup rate of the remaining newspapers at boxes is 70 percent."

PDF editions can offer real advantages to old-line newspapers, says Len Kubas, president of Kubas Consultants, a Toronto newspaper consulting firm.

"The PDF hybrid newspaper seems to be a logical extension of the paid, printed daily newspaper," says Kubas. "It reaches a different audience than buys or reads the paid printed daily, and they're very cost-effective. Newspapers benefit by re-purposing editorial, especially when the PDF version is an afternoon/evening newspaper and the main paid, printed daily is a morning newspaper."

Kubas sees real potential for PDF editions for targeted editions for demographics that are too niched to be served effectively by print editions, say for working women or retired seniors, or for special-interest editions in areas like business/finance.

Among British papers using the new free print-and-read service are The Guardian, whose G24 features Guardian Unlimited news content is updated every 15 minutes, and The Telegraph's Telegraph PM, a 10-page, multimedia newspaper published weekday afternoons at 4 and 5:30.

The Toronto Star is the first commercial newspaper in North America to publish a print-digital hybrid, according to Michael Babad, assistant managing editor for multimedia.

"The basic reasoning was that as technology evolves it provides a new medium for products for our readers and advertisers," he says. "Star PM is a true hybrid, it's been designed that way. We wanted to reach as broad as audience as possible."

All of Star PM's stories are original, says Babad. "None of the content is from that day's paper unless a story is updated."

And as Babad allows, it's still a work in progress. "We are in the midst of discussing content changes. Where we go will be in response to our readers' needs and how technology evolves."

But so far the feedback from readers has been positive. "We have people reading it at work and at home, and there is some anecdotal evidence of people printing it off and reading it when leaving the office," he says.

"We think we have something spectacular on our hands," says Babad. "What we are going to do next is kind of adjust from what we have learned in the past three months and take it from there."